Global analysis of transcriptome and metabolomics revealed that fatty acid synthesis and urea cycle process regulate the growth of chinese soft-shelled turtle

The Chinese soft-shelled turtle ( Pelodiscus sinensis ) is an economically important aquatic species, with its growth influenced by genetic factors, environmental conditions, nutritional status, and intestinal microbiota. Despite its slow growth rate, typically taking 2–3 years to reach market size, understanding the molecular mechanisms that regulate its growth is critical for optimizing breeding conditions and improving aquaculture sustainability. In this study, we carried out a multi-omics analysis in individuals of P. sinensis aged 2, 5, and 8 months to systematically disclose the biological mechanisms and explore how these mechanisms affect its growth and adaptive ability. We found significant changes in the composition of intestinal bacteria, with Fusobacteriota and Proteobacteria dominating at the phylum level and displaying increasingly intimate interactions as growth processed. Notable enrichments were observed in pathways related to arginine biosynthesis and glycine and serine metabolism in differentially expressed genes (DEGs), as well as steroid biosynthesis and steroid hormone biosynthesis pathways in differentially expressed metabolites (DEMs). Furthermore, fatty acid synthesis and the urea cycle were identified as key metabolic pathways essential for the breeding of Chinese soft-shelled turtles. This research provides insights that can be utilized to optimize feed formulations, enhance breeding efficiency, and promote the healthy growth of P. sinensis in aquaculture. • Fusobacteriota and Proteobacteria may have an important effect on the biosynthesis of fatty acids and hormones in Pelodiscus sinensis. • Arginine biosynthesis, glycine and serine metabolism and urea cycle pathway play an important roles in the development of Pelodiscus sinensis .